Hot hard start

[Sooners]

Next, I did lots of kicking, all throttle and choke positions...plug is dry as a bone. Obvioulsy not getting any wet fuel to it.

Ok. What idle jet, air slide, atomiser and needle do you have fitted? And I assume you're running a VHB 27?[/quote]

Yes, VHB 27AD. The bike came without a carb, so I bought two used VHB27's and without knowing the stock setup, I have tried various tunings, hoping to dial it in.
What I am running now is a 40 slide, 50 idle jet, V16 needle, 265P atomizer. Also a 7450.1 gr10 float, 60 choke jet and I believe the main jet is a 105.
BTW, one thing I was trying to learn, was the difference is between a "P" and "T" atomizer.

Also new discovery. I thought I'd kick it this morning, with ignition off, while cold, just to see how wet I get the plug...but even cold, I don't get any gas on the plug...basically I can't get the plug wet under any circumstance.

Greg, I'll try and get some pics posted later today.

[Sooners]

CarbOil 007.jpg

CarbOil 006.jpg

CarbOil 005.jpg

[Crazygreg]

Thanks a lot for the pictures!!

Something that might sound stupid regarding your plug... but which stopped my friend from starting his scrambler for a while (for a year or so he kind of gave up after trying 3 different carbs) :
> a piece of rag was by the inlet valve.... we had a good laugh about it!


Just realized you said it run when cold... did you check for an air leak by the rubber coupler? might get worst when hot...

[Ventodue]

Yes, VHB 27AD. I have tried various tunings, what I am running now is a 40 slide, 50 idle jet, V16 needle, 265P atomizer. Also a 7450.1 gr10 float, 60 choke jet and I believe the main jet is a 105.

Well, I can't see anything that is radically wrong there. However, seeing as we're trying to track a minor malfunction, I guess we may be looking for a minor discrepancy. So, following that line of thought:

1. The mains may be a little small. You could try upping to a 115 or a 120.

2. The needle could be changed for a V13. In the meanwhile, try lifting the existing needle a slot.

3. The slide could be changed to a 60 (if you can find one, that is - they ain't easy ...)

Otherwise, how worn is the slide? VHB slides are prone to wear and air may be leaking around the sides, upsetting the mixture at start-up.

... one thing I was trying to learn, was the difference is between a "P" and "T" atomizer.

According to this,* it's both length and holes: 'P' on the left, 'T' in the middle. Might be worth trying a 'T'?
(Source: http://www.thisoldtractor.com/gtbender/ ... mizers.htm)



* And seemingly confirmed on the UK Dell'Orto site:
http://www.dellorto.co.uk/merchandise/p ... ctionID=68

[Ventodue]

On the subject of trying to find the original specs for your carb, this guy seems to be a specialist on Condors (all the models, not just the Ducati powered ones).

http://www.benvanhelden.nl/Condorclub/
condorfreak@gmail.com

He’s in Holland, and I’m not sure how good his English might be. But perhaps you could try asking Eldert Rademaker, who's a member of this Forum, to contact him on your behalf?

[Sooners]

On the subject of trying to find the original specs for your carb, this guy seems to be a specialist on Condors (all the models, not just the Ducati powered ones).

http://www.benvanhelden.nl/Condorclub/
condorfreak@gmail.com

He’s in Holland, and I’m not sure how good his English might be. But perhaps you could try asking Eldert Rademaker, who's a member of this Forum, to contact him on your behalf?

Well guys...I think I have zero'ed in on the problem. Thanks for all your guidance and assistance.
This bike is evidently very sensitive on air intake during starting. It really needs the carburetor to be "closed", to pull the fuel in while kick starting. Two changes, seemed to fix my hot starting situation. One was opening the idle air screw more (from 2-1/2 to 3-1/2 turns), which in essence drops the throttle slide down, reducing air intake more. By doing this, the bike started to fire up on hot starts, and still starts on cold...just idling slower now on cold situations, which is really no problem. I just didn't realize this bike was that sensitive, with respect to both hot and cold starting. The other issue (thank you CrazyGerg), was the rubber coupler between the intake and engine. It is old and has many cracks and evidently leaking air, and thus affecting hot starts. I litterally wrapped a old sock around this rubber coupling, and the bike starting improved dramatically. Got me a new coupler on order. I had seen it was old and cracked but just didn't think it was a factor...so thanks for making me take a closer look.

Ventodue, I have sent a email to the guy you suggested...maybe he can advise on "factory" settings. I am curious to what those parameters are.
You were right on increasing the main. I had a 105 and the bike sputtered on near full throttle. I changed it to a 115, and now it's smooth as butter to wide open throttle...thanks. On the throttle slide, I actually have a 60, but since it has a shorter back side than the 40, as I talked above, it worsened my start up issue. The 40 is working fine now.

Thanks again for all your help, this is my first Ducati "toy", and this little bevel engine is a joy to tinker with, ride, and listen to it puff along.

[Ventodue]

I think I have zero'ed in on the problem. Two changes, seemed to fix my hot starting situation. One was opening the idle air screw more (from 2-1/2 to 3-1/2 turns) ... The other issue was the rubber coupler between the intake and engine <snip>

Excellent! Yep, as Greg pointed out, those rubber insulators are a well-known 'Usual Suspect' for running lean !